Wait for perfbot devices to charge between runs.

build/android/provision_devices.py

Index: build/android/provision_devices.py
diff --git a/build/android/provision_devices.py b/build/android/provision_devices.py
index 8433e01d7bec58ee6b781346544b2782ec14ac3b..b8f116fe242450a043f602df44d2b392bb4a6914 100755
--- a/build/android/provision_devices.py
+++ b/build/android/provision_devices.py
@@ -147,11 +147,30 @@ def ProvisionDevices(options):
     _ConfigureLocalProperties(device)
     device_settings.ConfigureContentSettingsDict(
         device, device_settings.DETERMINISTIC_DEVICE_SETTINGS)
-    # TODO(tonyg): We eventually want network on. However, currently radios
-    # can cause perfbots to drain faster than they charge.
     if 'perf' in os.environ.get('BUILDBOT_BUILDERNAME', '').lower():
+      # TODO(tonyg): We eventually want network on. However, currently radios
+      # can cause perfbots to drain faster than they charge.
       device_settings.ConfigureContentSettingsDict(
           device, device_settings.NETWORK_DISABLED_SETTINGS)
+      # Some perf bots run benchmarks with USB charging disabled which leads

[jbudorick, 2014/06/13 16:43:56]

Would we want to try to enable USB charging here if it's disabled?

+      # to gradual draining of the battery. We must wait for a full charge
+      # before starting a run in order to keep the devices online.
+      try:
+        battery_info = device_adb.old_interface.GetBatteryInfo()
+      except Exception as e:
+        battery_info = {}
+        logging.error('Unable to obtain battery info for %s, %s', serial, e)
+
+      while int(battery_info.get('level', 0)) < 95:
+        if (not battery_info.get('AC powered', None) == 'true' and
+            not battery_info.get('USB powered', None) == 'true' and
+            not battery_info.get('Wireless powered', None) == 'true'):
+          logging.error('Device is not charging')
+          break
+        logging.info('Waiting for device to charge. Current level=',
+                     battery_info.get('level', 0))
+        time.sleep(60)
+        battery_info = device.old_interface.GetBatteryInfo()
     device.old_interface.RunShellCommandWithSU('date -u %f' % time.time())
   try:
     device_utils.DeviceUtils.parallel(devices).Reboot(True)